Articulated beds have only recently achieved significant commercial success in the residential market and previously such beds were marketed for the most part as hospital or nursing home products and with such objectives were over-designed and overly complicated and as a result too costly for the residential or home market.
Over the last several decades, articulated chairs and sofas have achieved some commercial success in the residential market but only recently has such technology been adapted for the residential articulated bed marketplace.
A primary consideration in the design of articulated beds, and components therefor in the residential market, is ease of shipment because a container the size of an entire assembled articulated bed would not only be excessively large but too heavy for one delivery person to bring into the home and install.
One attempt at solving this problem is illustrated in the Elliott, U.S. Pat. No. 4,381,571 which shows an articulated mattress spring that is adapted to fit on top of and rest on a separate simple rectangular bed frame. The Elliott mattress frame includes large stationary "L" shaped side sections with cross members to provide support for axially oriented motor and screw assemblies that drive complicated four bar linkages at the four corners of the module that serve to raise and lower the head and leg sections of the mattress support. While Elliott suggests that these parts, numbering literally hundreds, may be disassembled for shipment, it is realistically not practical to have the purchaser reassemble this complex device in his or her home.
A similar articulated bed is illustrated in the Neumann, U.S. Pat. No. 4,120,057 and it shows a power system for an articulated mattress support and, like the Elliott design, is adapted to fit into a bed frame. The problem with the Neumann device is that it requires a large rectangular frame the size of the bed frame itself so that no size reduction is practically possible in the Neumann system.
Furthermore in the Elliott device the power module with drive motors, gearing and rocker shafts, requires that the rocker shafts be mounted in outboard bearings, i.e. bearings in the large rectangular frame described above and such outboard bearings denigrate from the capability of shipping the bed in easily carried containers without requiring any significant reassembly at the purchaser's location.
Other articulated beds are illustrated in the Muir, U.S. Pat. No. 1,397,773 and the Szemplack, et al., U.S. Pat. No. 3,051,965. The patent to Muir also shows a device for adjusting the articulated bed. Double motor-type systems are shown in the Taylor, U.S. Pat. No. 2,500,742. Another standard articulated bed frame is illustrated in Hanning, et al., U.S. Pat. No. 3,921,230.
In the related application, U.S. Ser. No. 597,525, now U.S. Pat. No. 5,063,623, we disclose a power module for an articulated bed assembly that fits into a completely standard bed frame. A mattress support is provided that has wooden planar panels hinged to one another with a stationary central section adapted to be bolted to the top of the standard bed frame, a pivotal head section connected to the central section, and pivotally interconnected thigh and foot sections. The power module has an elongated housing that supports separate electric drive motors, one for the head section and one for the thigh and foot sections. Drive gearing in the module transmits power from the motors to transversely mounted rocker shafts that have rocker arms at the ends thereof that respectively pivot the head and leg sections upwardly and downwardly with a suitable wand-type control that reversely controls the two motors.
In this prior application, the power module is connected to the underside of the central stationary section of the mattress support.
In the other related application, U.S. Ser. No. 308,412 Filed: Sep. 19, 1994, an articulated bed having a modified standard bed frame is described that supports an independent power module replaceable without disassembly of the frame. The modified frame is of the well-known horizontally collapsible angle iron-type with castered legs. The framing includes a pair of side rails each having head and foot rail portions pivotally connected thereto at their ends for packing and shipping, that interengage one another when assembled in the home.
The frame has inverted side rails so that the horizontally flat parts of the angle irons are on top, and its legs are somewhat lengthened to accommodate the underslung power module. After the frame is assembled in the home, a pair of "U" shaped cross members are attached across the frame and the power module is affixed to the tops of these cross members.
This design has many of the advantages of the power module and standard bed frame disclosed in our related application, U.S. Ser. No. 597,525 now U.S. Pat. No. 5,063,623.
It is a primary object of the present invention to provide an improved articulated bed assembly that is easier to ship and assemble than prior articulated beds.